Surgery: Peripheral Vascular Disease, Varicose Veins, Aortic Aneurysm, Dissection of Aorta Flashcards
Define critical limb ischaemia [3]
Critical limb ischaemia is the end-stage of peripheral arterial disease, where there is an inadequate supply of blood to a limb to allow it to function normally at rest.
- Far extreme of intermittent claudification: rest pain (often constant) due to inadequate supply of blood to a limb
- < 50 mmHg at ankle
- Gangrene & ulcers
Define acute limb ischaemia [1]
Refers to a rapid onset of ischaemia in a limb.
Typically, this is due to a thrombus blocking the arterial supply of a distal limb, similar to a thrombus blocking a coronary artery in myocardial infarction
Define intermittent claudification [1]
Describe the pain expereince in intermittent claudification
Intermittent claudication:
- a symptom of ischaemia in a limb, occurring during exertion and relieved by rest.
- It is typically a crampy, achy pain in the calf, thigh or buttock muscles associated with muscle fatigue when walking beyond a certain intensity.
- Patients describe a crampy pain that predictably occurs after walking a certain distance. After stopping and resting, the pain will disappear.
Describe the presenting features of critical limb ischaemia [3]
Pain at rest: this pain is typically described as a burning or aching sensation and is often worse at night
Non-healing wounds: Patients with CLI may develop non-healing wounds on their feet or legs. These wounds may be small or large and may be accompanied by drainage or an odour
Gangrene: In severe cases of CLI, patients may develop gangrene, which is the death of tissue due to lack of blood flow. Gangrene can cause the affected area to turn black and emit a foul odour
Diagnosis for CLI? [4]
ABPI
Duplex (Doppler US)
MRA / CTA
Diagnositic angiogram
Name [1] and describe the classification used for PAD [4]
Fontaine classification
Describe the therapy options for PAD? [6]
Diabetic control:
- Reduce HbA1C by 1-2%
Cholesterol control:
- Artovastatin 80mg (all patients)
- Simvastatin 40mg
BP control
Antiplatets:
- Clopidogrel - 1st line
- Aspirin
Anti-oxidants & vitamins
Management of claudification:
- supervised exercise programmes: reduce symptoms by improving collateral blood flow. exercise till point of pain
- Vasoactive drugs:
Naftidrofuryl oxalate (5-HT2 receptor antagonist that acts as a peripheral vasodilator)
Describe the surgical treament options for PAD [3]
Angioplasty:
- inserting a catheter through the arterial system under x-ray guidance
- at the site of the stenosis, a balloon is inflated to create space in the lumen. A stent is can be ( but not always) inserted to keep the artery open
Endarterectomy
- cutting the vessel open and removing the atheromatous plaque
Bypass surgery
- using a graft to bypass the blockage
- may have to remove valve in a vein
- can use prosthetic graft if needed (Goretex / PTFE)
- veins last longer that prosthetic grafts}
When is bypass preferred to angioplasty as first surgical option? [1]
If predicted survival of patient > 2 yrs
What are the 6Ps of acute limb ischaemia? [6]
Pale
Pulseless
Painful
Paralysed
Paraesthetic
Perisingly cold
How do you manage acute limb ischaemia? [6]
Acute emergency!
Endovascular thrombolysis:
- inserting a catheter through the arterial system to apply thrombolysis directly into the clot
Endovascular thrombectomy:
- inserting a catheter through the arterial system and removing the thrombus by aspiration or mechanical devices
Surgical thrombectomy
- cutting open the vessel and removing the thrombus
Endarterectomy
Bypass surgery
Amputation of the limb if it is not possible to restore the blood supply
Which test is used to assess PAD in the leg? [1]
Buerger’s test
Describe how Buerger’s test is used to assess PAD in the leg [2]
Two parts:
1. Part One
- lie patient on their back (supine).
- Lift the patient’s legs to an angle of 45 degrees at the hip.
- Hold them there for 1-2 minutes, looking for pallor.
- Pallor indicates the arterial supply is not adequate to overcome gravity, suggesting peripheral arterial disease.
- Buerger’s angle refers to the angle at which the leg is pale due to inadequate blood supply. For example, a Buerger’s angle of 30 degrees means that the legs go pale when lifted to 30 degrees.
2. Second Part
- The second part involves sitting the patient up with their legs hanging over the side of the bed. Blood will flow back into the legs assisted by gravity. In a healthy patient, the legs will remain a normal pink colour. In a patient with peripheral arterial disease, they will go:
* Blue initially, as the ischaemic tissue deoxygenates the blood
* Dark red after a short time, due to vasodilation in response to the waste products of anaerobic respiration
Describe the first line diagnostic tool to diagnose PAD? [2]
The ankle-brachial index (ABI) is a non-invasive tool for the assessment of vascular status:
The ratio of systolic blood pressure (SBP) in the ankle (around the lower calf) compared with the systolic blood pressure in the arm. These readings are taken manually using a Doppler probe.
For example, an ankle SBP of 80 and an arm SBP of 100 gives a ratio of 0.8 (80/100).
What are the results of normal, mild, moderate & severe PAD from ABI? [4]
0.9 – 1.3 is normal
0.6 – 0.9 indicates mild peripheral arterial disease
0.3 – 0.6 indicates moderate to severe peripheral arterial disease
Less than 0.3 indicates severe disease to critical ischaemic
An ABPI above 1.3 can indicate [] of the arteries, making them difficult to compress. This is more common in diabetic patients.
Calcification
Define aneurysm [1]
Localised dilatation of an artery greater than 1.5 normal size
AAA:
The most commonly adopted threshold is a diameter of [] cm or more
More than 90% of aneurysms originate below the [] arteries.
The most commonly adopted threshold is a diameter of 3 cm or more
More than 90% of aneurysms originate below the renal arteries
The commonest peripheral aneursym is where? [1]
Why is this clinically significant? [2]
Popliteal aneurysm:
- 50% of patients with popliteal aneurysm have bilateral popliteal aneurysms or an AAA
What age does screening occur for AAA? [1]
Which population? [1]
What is the screen? [1]
:All men at 65; ultrasound
Describe the presentation of AAA [3]
Most patients are asymptomatic.
Pulsatile & expansile mass
It may be discovered on routine screening or when it ruptures:
* Severe abdominal pain that may radiate to the back or groin
* Haemodynamic instability (hypotension and tachycardia)
* Pulsatile and expansile mass in the abdomen
* Collapse
* Loss of consciousness
Whar are the indications for AAA surgery? [3]
AAA >5.5cm
Rapid AAA enlargement: >1cm/yr
Symptomatic
Describe the surgical procedures used to treat AAA [2]
Open AAA surgery:
- cross clamp the AA above & below aneursym
- open aneursym and remove clot
- stitch in graft
Endovascular aneurysm repair (EVAR)
- A wire is passed under fluoroscopic guidance through the aneurysm sac and a stent-graft is inserted to occlude the aneurysm from the inside
- local anaesthetic
Describe the risk of open surgery to treat AAA [5]
Open surgery:
- cross clamping the aorta generates a huge increase in afterload and the cardiac stress this causes can result in on-table cardiac arrest.
- general anaesthetic and laparotomy are significant insults and if the patient has a very poor baseline function then they may not be able to survive the procedure: mortality - 5/10%
- MI
- Multiorgan failure
- Paraplegia: due to stoppage of blood supply to spinal cord
- Haemorrhage
- Infections (near bowel)
- Hernia
Define the term arterial dissection [1]
Disruption to the intimal layer (due to trauma, iatrogenic or spontaneous).
Blood doesn’t flow in normal channel & perfuse vessel & organs
Acts like a localised aneursym
A false lumen full of blood is formed within the wall of the aorta.
Describe the pathophysiology of aortic dissection [2]
Tear in the tunica intima of the wall of the aorta, allowing blood to flow between the layers of the wall of the aorta.
A false lumen full of blood is formed within the wall of the aorta.
Describe this complication of varciose veins [1]
Superficial thrombophlebitis
What is this complication of varicose veins? [1]
Lipodermatosclerosis
A 65-year-old man attends an abdominal aortic aneurysm (AAA) screening offered by his GP. On ultrasound, it is revealed that he has a supra-renal aneurysm that is 4.9 cm in diameter. When questioned he says he has no symptoms.
How should this patient be managed?
12-monthly ultrasound assessment
3-monthly ultrasound assessment
6-monthly ultrasound assessment
Referral to stop smoking services
Urgent referral to vascular surgery
A 65-year-old man attends an abdominal aortic aneurysm (AAA) screening offered by his GP. On ultrasound, it is revealed that he has a supra-renal aneurysm that is 4.9 cm in diameter. When questioned he says he has no symptoms.
How should this patient be managed?
12-monthly ultrasound assessment
3-monthly ultrasound assessment
6-monthly ultrasound assessment
Referral to stop smoking services
Urgent referral to vascular surgery
